Effect of rocker heel angle of walking shoe on gait mechanics and muscle activity

This study was to investigate the effects of rocker heel angle during walking on gait mechanics and muscle activity of lower extremity. While fifteen healthy men walked with two pairs of different rocker heel shoes (15 degrees and 20 degrees) and a pair of normal running shoes at 1.33 m/s on the treadmill, the joint kinematics and EMG signal were simultaneously recorded for I minute. Temporal variables of gait pattern and ankle, knee, hip and trunk angle were analyzed using 3D motion analysis at 100 Hz. Muscle activity of rectus femoris, tibialis anterior, biceps femoris and medial gastrocnemius were analyzed at 1000Hz. To compare statistical difference of each shoe, the one-way ANOVA with repeated measures was conducted. Knee joint angle was increased in 15 degrees rocker shoes than 200 rocker shoes at right toe off. Also knee joint in 15 degrees rocker heel shoes was more flexed than in other shoes. But ankle dorsiflexion angle was significantly decreased in 15 degrees rocker shoes compare to normal shoes at left heel strike while 20 degrees rocker shoes reduced dorsiflexion angle compared with normal shoes at right toe off. Muscle activity of lower extremity statistically changed in both rocker shoes during gait cycle on treadmill.